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[PATCH] ERROR out early on attempt to touch user indexes while they are being (re)built.
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* [PATCH] ERROR out early on attempt to touch user indexes while they are being (re)built.
@ 2019-09-12 14:35 Arseny Sher <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Arseny Sher @ 2019-09-12 14:35 UTC (permalink / raw)

Existing ReindexIsProcessingIndex check is consulted only in genam.c and thus
enforced only for system catalogs. Check it also in the planner, so that indexes
which are currently being rebuilt are never tried. Also cock SetReindexProcessing
in index_create to defend from index self usage during its creation.

Without this, VACUUM FULL or just CREATE INDEX might fail with something like

ERROR:  could not read block 3534 in file "base/41366676/56697497": read only 0 of 8192 bytes

if there are indexes which usage can be considered during these very
indexes (re)building, i.e. index expression scans indexed table.

Such error might seem scary, so catch this earlier.
---
 src/backend/catalog/index.c                | 22 ++++++++++++++++++++--
 src/backend/optimizer/util/plancat.c       |  9 +++++++++
 src/test/regress/expected/create_index.out | 15 +++++++++++++++
 src/test/regress/sql/create_index.sql      | 13 +++++++++++++
 4 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 3e1d40662d..5bc764ce46 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -1174,7 +1174,22 @@ index_create(Relation heapRelation,
 	}
 	else
 	{
-		index_build(heapRelation, indexRelation, indexInfo, false, true);
+		/* ensure SetReindexProcessing state isn't leaked */
+		PG_TRY();
+		{
+			/* Suppress use of the target index while building it */
+			SetReindexProcessing(heapRelationId, indexRelationId);
+
+			index_build(heapRelation, indexRelation, indexInfo, false, true);
+		}
+		PG_CATCH();
+		{
+			/* Make sure flag gets cleared on error exit */
+			ResetReindexProcessing();
+			PG_RE_THROW();
+		}
+		PG_END_TRY();
+		ResetReindexProcessing();
 	}
 
 	/*
@@ -1379,7 +1394,10 @@ index_concurrently_build(Oid heapRelationId,
 	indexInfo->ii_Concurrent = true;
 	indexInfo->ii_BrokenHotChain = false;
 
-	/* Now build the index */
+	/*
+	 * Now build the index
+	 * SetReindexProcessing is not required since indisvalid is false anyway
+	 */
 	index_build(heapRel, indexRelation, indexInfo, false, true);
 
 	/* Close both the relations, but keep the locks */
diff --git a/src/backend/optimizer/util/plancat.c b/src/backend/optimizer/util/plancat.c
index cf1761401d..e42471cac8 100644
--- a/src/backend/optimizer/util/plancat.c
+++ b/src/backend/optimizer/util/plancat.c
@@ -27,6 +27,7 @@
 #include "access/xlog.h"
 #include "catalog/catalog.h"
 #include "catalog/dependency.h"
+#include "catalog/index.h"
 #include "catalog/heap.h"
 #include "catalog/pg_am.h"
 #include "catalog/pg_proc.h"
@@ -199,6 +200,14 @@ get_relation_info(PlannerInfo *root, Oid relationObjectId, bool inhparent,
 			indexRelation = index_open(indexoid, lmode);
 			index = indexRelation->rd_index;
 
+			if (ReindexIsProcessingIndex(indexoid))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+						 errmsg("cannot use index %s which is currently being reindexed",
+								RelationGetRelationName(indexRelation)),
+						 errhint("Probably index expressions include functions "
+								 "accessing indexed table itself, but they must be immutable.")));
+
 			/*
 			 * Ignore invalid indexes, since they can't safely be used for
 			 * queries.  Note that this is OK because the data structure we
diff --git a/src/test/regress/expected/create_index.out b/src/test/regress/expected/create_index.out
index 324db1b6ae..f9aeb97ed8 100644
--- a/src/test/regress/expected/create_index.out
+++ b/src/test/regress/expected/create_index.out
@@ -1323,6 +1323,21 @@ create unique index hash_f8_index_1 on hash_f8_heap(abs(random));
 create unique index hash_f8_index_2 on hash_f8_heap((seqno + 1), random);
 create unique index hash_f8_index_3 on hash_f8_heap(random) where seqno > 1000;
 --
+-- Create an index which might consider using this very index during the build.
+--
+-- primary key ensures relhasindex is set
+CREATE TABLE pears(f1 int primary key, f2 int);
+INSERT INTO pears SELECT i, i+1 FROM generate_series(1, 100) i;
+CREATE FUNCTION pears_f(i int) RETURNS int LANGUAGE SQL IMMUTABLE AS $$
+  SELECT f1 FROM pears WHERE pears.f2 = 42
+$$;
+CREATE index ON pears ((pears_f(f1)));
+ERROR:  cannot use index pears_pears_f_idx which is currently being reindexed
+HINT:  Probably index expressions include functions accessing indexed table itself, but they must be immutable.
+CONTEXT:  SQL function "pears_f" during startup
+DROP TABLE pears;
+DROP FUNCTION pears_f;
+--
 -- Try some concurrent index builds
 --
 -- Unfortunately this only tests about half the code paths because there are
diff --git a/src/test/regress/sql/create_index.sql b/src/test/regress/sql/create_index.sql
index f96bebf410..76a781f6b0 100644
--- a/src/test/regress/sql/create_index.sql
+++ b/src/test/regress/sql/create_index.sql
@@ -446,6 +446,19 @@ create unique index hash_f8_index_2 on hash_f8_heap((seqno + 1), random);
 create unique index hash_f8_index_3 on hash_f8_heap(random) where seqno > 1000;
 
 --
+-- Create an index which might consider using this very index during the build.
+--
+-- primary key ensures relhasindex is set
+CREATE TABLE pears(f1 int primary key, f2 int);
+INSERT INTO pears SELECT i, i+1 FROM generate_series(1, 100) i;
+CREATE FUNCTION pears_f(i int) RETURNS int LANGUAGE SQL IMMUTABLE AS $$
+  SELECT f1 FROM pears WHERE pears.f2 = 42
+$$;
+CREATE index ON pears ((pears_f(f1)));
+DROP TABLE pears;
+DROP FUNCTION pears_f;
+
+--
 -- Try some concurrent index builds
 --
 -- Unfortunately this only tests about half the code paths because there are
-- 
2.11.0


--=-=-=--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2019-11-08 13:12 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2019-11-08 13:12 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size.

In psql, include a new "Free" column in \db+ output.
---
 doc/src/sgml/func.sgml          | 21 ++++++++
 doc/src/sgml/ref/psql-ref.sgml  |  2 +-
 src/backend/utils/adt/dbsize.c  | 94 +++++++++++++++++++++++++++++++++
 src/bin/psql/describe.c         | 11 ++--
 src/include/catalog/pg_proc.dat |  8 +++
 5 files changed, 132 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..3a2f47c50ec 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_bsize; /* available blocks times block size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
-- 
2.47.2


--vqKhBUYnSUFh3RIa--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v8] Avoid orphaned objects dependencies
@ 2024-03-29 15:43 Bertrand Drouvot <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Bertrand Drouvot @ 2024-03-29 15:43 UTC (permalink / raw)

It's currently possible to create orphaned objects dependencies, for example:

Scenario 1:

session 1: begin; drop schema schem;
session 2: create a function in the schema schem
session 1: commit;

With the above, the function created in session 2 would be linked to a non
existing schema.

Scenario 2:

session 1: begin; create a function in the schema schem
session 2: drop schema schem;
session 1: commit;

With the above, the function created in session 1 would be linked to a non
existing schema.

To avoid those scenarios, a new lock (that conflicts with a lock taken by DROP)
has been put in place when the dependencies are being recorded. With this in
place, the drop schema in scenario 2 would be locked.

Also, after the new lock attempt, the patch checks that the object still exists:
with this in place session 2 in scenario 1 would be locked and would report an
error once session 1 committs (that would not be the case should session 1 abort
the transaction).

If the object is dropped before the new lock attempt is triggered then the patch
would also report an error (but with less details).

The patch adds a few tests for some dependency cases (that would currently produce
orphaned objects):

- schema and function (as the above scenarios)
- alter a dependency (function and schema)
- function and arg type
- function and return type
- function and function
- domain and domain
- table and type
- server and foreign data wrapper
---
 src/backend/catalog/dependency.c              |  59 ++++++++
 src/backend/catalog/objectaddress.c           |  66 +++++++++
 src/backend/catalog/pg_depend.c               |  12 ++
 src/backend/utils/errcodes.txt                |   1 +
 src/include/catalog/dependency.h              |   1 +
 src/include/catalog/objectaddress.h           |   1 +
 .../expected/test_dependencies_locks.out      | 129 ++++++++++++++++++
 src/test/isolation/isolation_schedule         |   1 +
 .../specs/test_dependencies_locks.spec        |  89 ++++++++++++
 9 files changed, 359 insertions(+)
  24.3% src/backend/catalog/
  45.3% src/test/isolation/expected/
  28.2% src/test/isolation/specs/

diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index d4b5b2ade1..4271ed7c5b 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1517,6 +1517,65 @@ AcquireDeletionLock(const ObjectAddress *object, int flags)
 	}
 }
 
+/*
+ * depLockAndCheckObject
+ *
+ * Lock the object that we are about to record a dependency on.
+ * After it's locked, verify that it hasn't been dropped while we
+ * weren't looking.  If the object has been dropped, this function
+ * does not return!
+ */
+void
+depLockAndCheckObject(const ObjectAddress *object)
+{
+	char	   *object_description;
+
+	/*
+	 * Those don't rely on LockDatabaseObject() when being dropped (see
+	 * AcquireDeletionLock()). Also it looks like they can not produce
+	 * orphaned dependent objects when being dropped.
+	 */
+	if (object->classId == RelationRelationId || object->classId == AuthMemRelationId)
+		return;
+
+	object_description = getObjectDescription(object, true);
+
+	/* assume we should lock the whole object not a sub-object */
+	LockDatabaseObject(object->classId, object->objectId, 0, AccessShareLock);
+
+	/* check if object still exists */
+	if (!ObjectByIdExist(object, false))
+	{
+		/*
+		 * It might be possible that we are creating it (for example creating
+		 * a composite type while creating a relation), so bypass the syscache
+		 * lookup and use a SnapshotSelf snapshot instead to cover this
+		 * scenario.
+		 */
+		if (!ObjectByIdExist(object, true))
+		{
+			/*
+			 * If the object has been dropped before we get a chance to get
+			 * its description, then emit a generic error message. That looks
+			 * like a good compromise over extra complexity.
+			 */
+			if (object_description)
+				ereport(ERROR,
+						(errcode(ERRCODE_DEPENDENT_OBJECTS_DOES_NOT_EXIST),
+						 errmsg("%s does not exist", object_description)));
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_DEPENDENT_OBJECTS_DOES_NOT_EXIST),
+						 errmsg("a dependent object does not exist")));
+		}
+	}
+
+	if (object_description)
+		pfree(object_description);
+
+	return;
+}
+
 /*
  * ReleaseDeletionLock - release an object deletion lock
  *
diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c
index 7b536ac6fd..115cb1572e 100644
--- a/src/backend/catalog/objectaddress.c
+++ b/src/backend/catalog/objectaddress.c
@@ -2590,6 +2590,72 @@ get_object_namespace(const ObjectAddress *address)
 	return oid;
 }
 
+/*
+ * ObjectByIdExist
+ *
+ * Return whether the given object exists.
+ *
+ * Works for most catalogs, if no special processing is needed.
+ */
+bool
+ObjectByIdExist(const ObjectAddress *address, bool use_snapshot_self)
+{
+	HeapTuple	tuple;
+	int			cache = -1;
+	const ObjectPropertyType *property;
+
+	if (!use_snapshot_self)
+	{
+		property = get_object_property_data(address->classId);
+
+		cache = property->oid_catcache_id;
+	}
+
+	if (cache >= 0)
+	{
+		/* Fetch tuple from syscache. */
+		tuple = SearchSysCache1(cache, ObjectIdGetDatum(address->objectId));
+
+		if (!HeapTupleIsValid(tuple))
+		{
+			return false;
+		}
+
+		ReleaseSysCache(tuple);
+
+		return true;
+	}
+	else
+	{
+		Relation	rel;
+		ScanKeyData skey[1];
+		SysScanDesc scan;
+		Snapshot	snapshot;
+
+		if (use_snapshot_self)
+			snapshot = SnapshotSelf;
+		else
+			snapshot = NULL;
+
+		rel = table_open(address->classId, AccessShareLock);
+
+		ScanKeyInit(&skey[0],
+					get_object_attnum_oid(address->classId),
+					BTEqualStrategyNumber, F_OIDEQ,
+					ObjectIdGetDatum(address->objectId));
+
+		scan = systable_beginscan(rel, get_object_oid_index(address->classId), true,
+								  snapshot, 1, skey);
+
+		/* we expect exactly one match */
+		tuple = systable_getnext(scan);
+		systable_endscan(scan);
+		table_close(rel, AccessShareLock);
+
+		return (HeapTupleIsValid(tuple));
+	}
+}
+
 /*
  * Return ObjectType for the given object type as given by
  * getObjectTypeDescription; if no valid ObjectType code exists, but it's a
diff --git a/src/backend/catalog/pg_depend.c b/src/backend/catalog/pg_depend.c
index 5366f7820c..f16af28429 100644
--- a/src/backend/catalog/pg_depend.c
+++ b/src/backend/catalog/pg_depend.c
@@ -108,6 +108,12 @@ recordMultipleDependencies(const ObjectAddress *depender,
 		if (isObjectPinned(referenced))
 			continue;
 
+		/*
+		 * Acquire a lock and check object still exists while recording the
+		 * dependency. XXX - Should we do so only for DEPENDENCY_NORMAL?
+		 */
+		depLockAndCheckObject(referenced);
+
 		if (slot_init_count < max_slots)
 		{
 			slot[slot_stored_count] = MakeSingleTupleTableSlot(RelationGetDescr(dependDesc),
@@ -506,6 +512,12 @@ changeDependencyFor(Oid classId, Oid objectId,
 		return 1;
 	}
 
+	/*
+	 * Acquire a lock and check object still exists while changing the
+	 * dependency.
+	 */
+	depLockAndCheckObject(&objAddr);
+
 	depRel = table_open(DependRelationId, RowExclusiveLock);
 
 	/* There should be existing dependency record(s), so search. */
diff --git a/src/backend/utils/errcodes.txt b/src/backend/utils/errcodes.txt
index 3250d539e1..60e8539fe3 100644
--- a/src/backend/utils/errcodes.txt
+++ b/src/backend/utils/errcodes.txt
@@ -271,6 +271,7 @@ Section: Class 28 - Invalid Authorization Specification
 Section: Class 2B - Dependent Privilege Descriptors Still Exist
 
 2B000    E    ERRCODE_DEPENDENT_PRIVILEGE_DESCRIPTORS_STILL_EXIST            dependent_privilege_descriptors_still_exist
+2BP02    E    ERRCODE_DEPENDENT_OBJECTS_DOES_NOT_EXIST                       dependent_objects_does_not_exist
 2BP01    E    ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST                          dependent_objects_still_exist
 
 Section: Class 2D - Invalid Transaction Termination
diff --git a/src/include/catalog/dependency.h b/src/include/catalog/dependency.h
index 7eee66f810..5619b6f55e 100644
--- a/src/include/catalog/dependency.h
+++ b/src/include/catalog/dependency.h
@@ -101,6 +101,7 @@ typedef struct ObjectAddresses ObjectAddresses;
 /* in dependency.c */
 
 extern void AcquireDeletionLock(const ObjectAddress *object, int flags);
+extern void depLockAndCheckObject(const ObjectAddress *object);
 
 extern void ReleaseDeletionLock(const ObjectAddress *object);
 
diff --git a/src/include/catalog/objectaddress.h b/src/include/catalog/objectaddress.h
index 3a70d80e32..53ee9ad9e6 100644
--- a/src/include/catalog/objectaddress.h
+++ b/src/include/catalog/objectaddress.h
@@ -53,6 +53,7 @@ extern void check_object_ownership(Oid roleid,
 								   Node *object, Relation relation);
 
 extern Oid	get_object_namespace(const ObjectAddress *address);
+extern bool ObjectByIdExist(const ObjectAddress *address, bool use_snapshot_self);
 
 extern bool is_objectclass_supported(Oid class_id);
 extern const char *get_object_class_descr(Oid class_id);
diff --git a/src/test/isolation/expected/test_dependencies_locks.out b/src/test/isolation/expected/test_dependencies_locks.out
new file mode 100644
index 0000000000..9b645d7aa5
--- /dev/null
+++ b/src/test/isolation/expected/test_dependencies_locks.out
@@ -0,0 +1,129 @@
+Parsed test spec with 2 sessions
+
+starting permutation: s1_begin s1_create_function_in_schema s2_drop_schema s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_in_schema: CREATE FUNCTION testschema.foo() RETURNS int AS 'select 1' LANGUAGE sql;
+step s2_drop_schema: DROP SCHEMA testschema; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_schema: <... completed>
+ERROR:  cannot drop schema testschema because other objects depend on it
+
+starting permutation: s2_begin s2_drop_schema s1_create_function_in_schema s2_commit
+step s2_begin: BEGIN;
+step s2_drop_schema: DROP SCHEMA testschema;
+step s1_create_function_in_schema: CREATE FUNCTION testschema.foo() RETURNS int AS 'select 1' LANGUAGE sql; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_in_schema: <... completed>
+ERROR:  schema testschema does not exist
+
+starting permutation: s1_begin s1_alter_function_schema s2_drop_alterschema s1_commit
+step s1_begin: BEGIN;
+step s1_alter_function_schema: ALTER FUNCTION public.falter() SET SCHEMA alterschema;
+step s2_drop_alterschema: DROP SCHEMA alterschema; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_alterschema: <... completed>
+ERROR:  cannot drop schema alterschema because other objects depend on it
+
+starting permutation: s2_begin s2_drop_alterschema s1_alter_function_schema s2_commit
+step s2_begin: BEGIN;
+step s2_drop_alterschema: DROP SCHEMA alterschema;
+step s1_alter_function_schema: ALTER FUNCTION public.falter() SET SCHEMA alterschema; <waiting ...>
+step s2_commit: COMMIT;
+step s1_alter_function_schema: <... completed>
+ERROR:  schema alterschema does not exist
+
+starting permutation: s1_begin s1_create_function_with_argtype s2_drop_foo_type s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_with_argtype: CREATE FUNCTION fooargtype(num foo) RETURNS int AS 'select 1' LANGUAGE sql;
+step s2_drop_foo_type: DROP TYPE public.foo; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_foo_type: <... completed>
+ERROR:  cannot drop type foo because other objects depend on it
+
+starting permutation: s2_begin s2_drop_foo_type s1_create_function_with_argtype s2_commit
+step s2_begin: BEGIN;
+step s2_drop_foo_type: DROP TYPE public.foo;
+step s1_create_function_with_argtype: CREATE FUNCTION fooargtype(num foo) RETURNS int AS 'select 1' LANGUAGE sql; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_with_argtype: <... completed>
+ERROR:  type foo does not exist
+
+starting permutation: s1_begin s1_create_function_with_rettype s2_drop_foo_rettype s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_with_rettype: CREATE FUNCTION footrettype() RETURNS id LANGUAGE sql RETURN 1;
+step s2_drop_foo_rettype: DROP DOMAIN id; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_foo_rettype: <... completed>
+ERROR:  cannot drop type id because other objects depend on it
+
+starting permutation: s2_begin s2_drop_foo_rettype s1_create_function_with_rettype s2_commit
+step s2_begin: BEGIN;
+step s2_drop_foo_rettype: DROP DOMAIN id;
+step s1_create_function_with_rettype: CREATE FUNCTION footrettype() RETURNS id LANGUAGE sql RETURN 1; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_with_rettype: <... completed>
+ERROR:  type id does not exist
+
+starting permutation: s1_begin s1_create_function_with_function s2_drop_function_f s1_commit
+step s1_begin: BEGIN;
+step s1_create_function_with_function: CREATE FUNCTION foofunc() RETURNS int LANGUAGE SQL RETURN f() + 1;
+step s2_drop_function_f: DROP FUNCTION f(); <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_function_f: <... completed>
+ERROR:  cannot drop function f() because other objects depend on it
+
+starting permutation: s2_begin s2_drop_function_f s1_create_function_with_function s2_commit
+step s2_begin: BEGIN;
+step s2_drop_function_f: DROP FUNCTION f();
+step s1_create_function_with_function: CREATE FUNCTION foofunc() RETURNS int LANGUAGE SQL RETURN f() + 1; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_function_with_function: <... completed>
+ERROR:  function f() does not exist
+
+starting permutation: s1_begin s1_create_domain_with_domain s2_drop_domain_id s1_commit
+step s1_begin: BEGIN;
+step s1_create_domain_with_domain: CREATE DOMAIN idid as id;
+step s2_drop_domain_id: DROP DOMAIN id; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_domain_id: <... completed>
+ERROR:  cannot drop type id because other objects depend on it
+
+starting permutation: s2_begin s2_drop_domain_id s1_create_domain_with_domain s2_commit
+step s2_begin: BEGIN;
+step s2_drop_domain_id: DROP DOMAIN id;
+step s1_create_domain_with_domain: CREATE DOMAIN idid as id; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_domain_with_domain: <... completed>
+ERROR:  type id does not exist
+
+starting permutation: s1_begin s1_create_table_with_type s2_drop_footab_type s1_commit
+step s1_begin: BEGIN;
+step s1_create_table_with_type: CREATE TABLE tabtype(a footab);
+step s2_drop_footab_type: DROP TYPE public.footab; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_footab_type: <... completed>
+ERROR:  cannot drop type footab because other objects depend on it
+
+starting permutation: s2_begin s2_drop_footab_type s1_create_table_with_type s2_commit
+step s2_begin: BEGIN;
+step s2_drop_footab_type: DROP TYPE public.footab;
+step s1_create_table_with_type: CREATE TABLE tabtype(a footab); <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_table_with_type: <... completed>
+ERROR:  type footab does not exist
+
+starting permutation: s1_begin s1_create_server_with_fdw_wrapper s2_drop_fdw_wrapper s1_commit
+step s1_begin: BEGIN;
+step s1_create_server_with_fdw_wrapper: CREATE SERVER srv_fdw_wrapper FOREIGN DATA WRAPPER fdw_wrapper;
+step s2_drop_fdw_wrapper: DROP FOREIGN DATA WRAPPER fdw_wrapper RESTRICT; <waiting ...>
+step s1_commit: COMMIT;
+step s2_drop_fdw_wrapper: <... completed>
+ERROR:  cannot drop foreign-data wrapper fdw_wrapper because other objects depend on it
+
+starting permutation: s2_begin s2_drop_fdw_wrapper s1_create_server_with_fdw_wrapper s2_commit
+step s2_begin: BEGIN;
+step s2_drop_fdw_wrapper: DROP FOREIGN DATA WRAPPER fdw_wrapper RESTRICT;
+step s1_create_server_with_fdw_wrapper: CREATE SERVER srv_fdw_wrapper FOREIGN DATA WRAPPER fdw_wrapper; <waiting ...>
+step s2_commit: COMMIT;
+step s1_create_server_with_fdw_wrapper: <... completed>
+ERROR:  foreign-data wrapper fdw_wrapper does not exist
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 0342eb39e4..1b67f0bffe 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -114,3 +114,4 @@ test: serializable-parallel-2
 test: serializable-parallel-3
 test: matview-write-skew
 test: lock-nowait
+test: test_dependencies_locks
diff --git a/src/test/isolation/specs/test_dependencies_locks.spec b/src/test/isolation/specs/test_dependencies_locks.spec
new file mode 100644
index 0000000000..5d04dfe9dc
--- /dev/null
+++ b/src/test/isolation/specs/test_dependencies_locks.spec
@@ -0,0 +1,89 @@
+setup
+{
+  CREATE SCHEMA testschema;
+  CREATE SCHEMA alterschema;
+  CREATE TYPE public.foo as enum ('one', 'two');
+  CREATE TYPE public.footab as enum ('three', 'four');
+  CREATE DOMAIN id AS int;
+  CREATE FUNCTION f() RETURNS int LANGUAGE SQL RETURN 1;
+  CREATE FUNCTION public.falter() RETURNS int LANGUAGE SQL RETURN 1;
+  CREATE FOREIGN DATA WRAPPER fdw_wrapper;
+}
+
+teardown
+{
+  DROP FUNCTION IF EXISTS testschema.foo();
+  DROP FUNCTION IF EXISTS fooargtype(num foo);
+  DROP FUNCTION IF EXISTS footrettype();
+  DROP FUNCTION IF EXISTS foofunc();
+  DROP FUNCTION IF EXISTS public.falter();
+  DROP FUNCTION IF EXISTS alterschema.falter();
+  DROP DOMAIN IF EXISTS idid;
+  DROP SERVER IF EXISTS srv_fdw_wrapper;
+  DROP TABLE IF EXISTS tabtype;
+  DROP SCHEMA IF EXISTS testschema;
+  DROP SCHEMA IF EXISTS alterschema;
+  DROP TYPE IF EXISTS public.foo;
+  DROP TYPE IF EXISTS public.footab;
+  DROP DOMAIN IF EXISTS id;
+  DROP FUNCTION IF EXISTS f();
+  DROP FOREIGN DATA WRAPPER IF EXISTS fdw_wrapper;
+}
+
+session "s1"
+
+step "s1_begin" { BEGIN; }
+step "s1_create_function_in_schema" { CREATE FUNCTION testschema.foo() RETURNS int AS 'select 1' LANGUAGE sql; }
+step "s1_create_function_with_argtype" { CREATE FUNCTION fooargtype(num foo) RETURNS int AS 'select 1' LANGUAGE sql; }
+step "s1_create_function_with_rettype" { CREATE FUNCTION footrettype() RETURNS id LANGUAGE sql RETURN 1; }
+step "s1_create_function_with_function" { CREATE FUNCTION foofunc() RETURNS int LANGUAGE SQL RETURN f() + 1; }
+step "s1_alter_function_schema" { ALTER FUNCTION public.falter() SET SCHEMA alterschema; }
+step "s1_create_domain_with_domain" { CREATE DOMAIN idid as id; }
+step "s1_create_table_with_type" { CREATE TABLE tabtype(a footab); }
+step "s1_create_server_with_fdw_wrapper" { CREATE SERVER srv_fdw_wrapper FOREIGN DATA WRAPPER fdw_wrapper; }
+step "s1_commit" { COMMIT; }
+
+session "s2"
+
+step "s2_begin" { BEGIN; }
+step "s2_drop_schema" { DROP SCHEMA testschema; }
+step "s2_drop_alterschema" { DROP SCHEMA alterschema; }
+step "s2_drop_foo_type" { DROP TYPE public.foo; }
+step "s2_drop_foo_rettype" { DROP DOMAIN id; }
+step "s2_drop_footab_type" { DROP TYPE public.footab; }
+step "s2_drop_function_f" { DROP FUNCTION f(); }
+step "s2_drop_domain_id" { DROP DOMAIN id; }
+step "s2_drop_fdw_wrapper" { DROP FOREIGN DATA WRAPPER fdw_wrapper RESTRICT; }
+step "s2_commit" { COMMIT; }
+
+# function - schema
+permutation "s1_begin" "s1_create_function_in_schema" "s2_drop_schema" "s1_commit"
+permutation "s2_begin" "s2_drop_schema" "s1_create_function_in_schema" "s2_commit"
+
+# alter function - schema
+permutation "s1_begin" "s1_alter_function_schema" "s2_drop_alterschema" "s1_commit"
+permutation "s2_begin" "s2_drop_alterschema" "s1_alter_function_schema" "s2_commit"
+
+# function - argtype
+permutation "s1_begin" "s1_create_function_with_argtype" "s2_drop_foo_type" "s1_commit"
+permutation "s2_begin" "s2_drop_foo_type" "s1_create_function_with_argtype" "s2_commit"
+
+# function - rettype
+permutation "s1_begin" "s1_create_function_with_rettype" "s2_drop_foo_rettype" "s1_commit"
+permutation "s2_begin" "s2_drop_foo_rettype" "s1_create_function_with_rettype" "s2_commit"
+
+# function - function
+permutation "s1_begin" "s1_create_function_with_function" "s2_drop_function_f" "s1_commit"
+permutation "s2_begin" "s2_drop_function_f" "s1_create_function_with_function" "s2_commit"
+
+# domain - domain
+permutation "s1_begin" "s1_create_domain_with_domain" "s2_drop_domain_id" "s1_commit"
+permutation "s2_begin" "s2_drop_domain_id" "s1_create_domain_with_domain" "s2_commit"
+
+# table - type
+permutation "s1_begin" "s1_create_table_with_type" "s2_drop_footab_type" "s1_commit"
+permutation "s2_begin" "s2_drop_footab_type" "s1_create_table_with_type" "s2_commit"
+
+# server - foreign data wrapper
+permutation "s1_begin" "s1_create_server_with_fdw_wrapper" "s2_drop_fdw_wrapper" "s1_commit"
+permutation "s2_begin" "s2_drop_fdw_wrapper" "s1_create_server_with_fdw_wrapper" "s2_commit"
-- 
2.34.1


--Z+BFS5G1lhqjvsq4--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   | 21 ++++++
 doc/src/sgml/ref/psql-ref.sgml           |  2 +-
 src/backend/utils/adt/dbsize.c           | 94 ++++++++++++++++++++++++
 src/bin/psql/describe.c                  | 11 ++-
 src/include/catalog/pg_proc.dat          |  8 ++
 src/test/regress/expected/tablespace.out | 21 ++++++
 src/test/regress/sql/tablespace.sql      | 10 +++
 7 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..30e0cb8d111 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,11 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +321,95 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL) == false)
+		return -1;
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+		return -1;
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--65NGEM4fhwMw73YU--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v5] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 189 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 72038fc835f..959b0b673ab 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 7c05afd4719..1ea67b3659f 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..b395824ca3f 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e1449654f96..36486417a48 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -234,7 +234,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -245,15 +245,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 190000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  wHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -1008,7 +1027,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index fa9ae79082b..78c03ea6412 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7866,6 +7866,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--sW4eVZZF7egqrnKF--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v4] Add pg_tablespace_avail() functions
@ 2025-03-14 15:29 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2025-03-14 15:29 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func.sgml                   |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 102 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  11 ++-
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 171 insertions(+), 4 deletions(-)

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 51dd8ad6571..0b4456ad958 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -30093,6 +30093,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index cedccc14129..9e1bec0b422 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1492,7 +1492,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index 25865b660ef..9bd8667c2d9 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,102 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space of tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+		elog(ERROR, "GetDiskFreeSpaceEx failed: error code %lu", GetLastError());
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not statvfs directory \"%s\": %m", tblspcPath)));
+	}
+
+	return fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index e6cf468ac9e..8c52a126ac1 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -241,10 +241,15 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 180000)
+			appendPQExpBuffer(&buf,
+							  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(oid)) AS \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 42e427f8fe8..9d64da6bfb8 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7680,6 +7680,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'disk stats for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index a90e39e5738..6709ed794df 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index dfe3db096e2..3fcd4bb00ff 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.47.2


--mxigUiQ2jY+Id+Rf--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v7] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  29 ++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 195 insertions(+), 6 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index ad9c8affb4f..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--Vrlrh/SZa9M0BUO9--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--





^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread

* [PATCH v6] Add pg_tablespace_avail() functions
@ 2026-07-21 13:08 Christoph Berg <[email protected]>
  0 siblings, 0 replies; 1192+ messages in thread

From: Christoph Berg @ 2026-07-21 13:08 UTC (permalink / raw)

This exposes the f_avail value from statvfs() on tablespace directories
on the SQL level, allowing monitoring of free disk space from within the
server. On windows, GetDiskFreeSpaceEx() is used.

Permissions required match those from pg_tablespace_size().

In psql, include a new "Free" column in \db+ output.

Add test coverage for pg_tablespace_avail() and the previously not
covered pg_tablespace_size() function.
---
 doc/src/sgml/func/func-admin.sgml        |  21 +++++
 doc/src/sgml/ref/psql-ref.sgml           |   2 +-
 src/backend/utils/adt/dbsize.c           | 110 +++++++++++++++++++++++
 src/bin/psql/describe.c                  |  32 +++++--
 src/include/catalog/pg_proc.dat          |   8 ++
 src/test/regress/expected/tablespace.out |  21 +++++
 src/test/regress/sql/tablespace.sql      |  10 +++
 7 files changed, 197 insertions(+), 7 deletions(-)

diff --git a/doc/src/sgml/func/func-admin.sgml b/doc/src/sgml/func/func-admin.sgml
index 0eae1c1f616..de29fb2b4fc 100644
--- a/doc/src/sgml/func/func-admin.sgml
+++ b/doc/src/sgml/func/func-admin.sgml
@@ -1755,6 +1755,27 @@ postgres=# SELECT '0/0'::pg_lsn + pd.segment_number * ps.setting::int + :offset
        </para></entry>
       </row>
 
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>pg_tablespace_avail</primary>
+        </indexterm>
+        <function>pg_tablespace_avail</function> ( <type>name</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para role="func_signature">
+        <function>pg_tablespace_avail</function> ( <type>oid</type> )
+        <returnvalue>bigint</returnvalue>
+       </para>
+       <para>
+        Returns the available disk space in the file system hosting the tablespace with the
+        specified name or OID. To use this function, you must
+        have <literal>CREATE</literal> privilege on the specified tablespace
+        or have privileges of the <literal>pg_read_all_stats</literal> role,
+        unless it is the default tablespace for the current database.
+       </para></entry>
+      </row>
+
       <row>
        <entry role="func_table_entry"><para role="func_signature">
         <indexterm>
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 56c2692e618..c7efa652052 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1501,7 +1501,7 @@ SELECT $1 \parse stmt1
         If <literal>x</literal> is appended to the command name, the results
         are displayed in expanded mode.
         If <literal>+</literal> is appended to the command name, each tablespace
-        is listed with its associated options, on-disk size, permissions and
+        is listed with its associated options, on-disk size and free disk space, permissions and
         description.
         </para>
         </listitem>
diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index cccc4a24c84..ae061fbf56b 100644
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -12,6 +12,12 @@
 #include "postgres.h"
 
 #include <sys/stat.h>
+#ifdef WIN32
+#include <fileapi.h>
+#include <errhandlingapi.h>
+#else
+#include <sys/statvfs.h>
+#endif
 
 #include "access/htup_details.h"
 #include "access/relation.h"
@@ -316,6 +322,110 @@ pg_tablespace_size_name(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ * Return available disk space for tablespace. Returns -1 if the tablespace
+ * directory cannot be found.
+ */
+static int64
+calculate_tablespace_avail(Oid tblspcOid)
+{
+	char		tblspcPath[MAXPGPATH];
+	AclResult	aclresult;
+#ifdef WIN32
+	ULARGE_INTEGER lpFreeBytesAvailable;
+#else
+	struct statvfs fst;
+#endif
+
+	/*
+	 * User must have privileges of pg_read_all_stats or have CREATE privilege
+	 * for target tablespace, either explicitly granted or implicitly because
+	 * it is default for current database.
+	 */
+	if (tblspcOid != MyDatabaseTableSpace &&
+		!has_privs_of_role(GetUserId(), ROLE_PG_READ_ALL_STATS))
+	{
+		aclresult = object_aclcheck(TableSpaceRelationId, tblspcOid, GetUserId(), ACL_CREATE);
+		if (aclresult != ACLCHECK_OK)
+			aclcheck_error(aclresult, OBJECT_TABLESPACE,
+						   get_tablespace_name(tblspcOid));
+	}
+
+	if (tblspcOid == DEFAULTTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "base");
+	else if (tblspcOid == GLOBALTABLESPACE_OID)
+		snprintf(tblspcPath, MAXPGPATH, "global");
+	else
+		snprintf(tblspcPath, MAXPGPATH, "%s/%u/%s", PG_TBLSPC_DIR, tblspcOid,
+				 TABLESPACE_VERSION_DIRECTORY);
+
+#ifdef WIN32
+	if (! GetDiskFreeSpaceEx(tblspcPath, &lpFreeBytesAvailable, NULL, NULL))
+	{
+		_dosmaperr(GetLastError());
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return lpFreeBytesAvailable.QuadPart; /* ULONGLONG part of ULARGE_INTEGER */
+#else
+	if (statvfs(tblspcPath, &fst) < 0)
+	{
+		if (errno == ENOENT)
+			return -1;
+		else
+			ereport(ERROR,
+					(errcode_for_file_access(),
+					 errmsg("could not get free disk space in tablespace directory \"%s\": %m", tblspcPath)));
+	}
+
+	return (int64) fst.f_bavail * fst.f_frsize; /* available blocks times fragment size */
+#endif
+}
+
+Datum
+pg_tablespace_avail_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tblspcOid = PG_GETARG_OID(0);
+	int64		avail;
+
+	/*
+	 * Not needed for correctness, but avoid non-user-facing error message
+	 * later if the tablespace doesn't exist.
+	 */
+	if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+		ereport(ERROR,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg("tablespace with OID %u does not exist", tblspcOid));
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+Datum
+pg_tablespace_avail_name(PG_FUNCTION_ARGS)
+{
+	Name		tblspcName = PG_GETARG_NAME(0);
+	Oid			tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
+	int64		avail;
+
+	avail = calculate_tablespace_avail(tblspcOid);
+
+	if (avail < 0)
+		PG_RETURN_NULL();
+
+	PG_RETURN_INT64(avail);
+}
+
+
 /*
  * calculate size of (one fork of) a relation
  *
diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index a2f09c26369..06eda474100 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -224,7 +224,7 @@ describeTablespaces(const char *pattern, bool verbose)
 	appendPQExpBuffer(&buf,
 					  "SELECT spcname AS \"%s\",\n"
 					  "  pg_catalog.pg_get_userbyid(spcowner) AS \"%s\",\n"
-					  "  pg_catalog.pg_tablespace_location(oid) AS \"%s\"",
+					  "  pg_catalog.pg_tablespace_location(tblspc.oid) AS \"%s\"",
 					  gettext_noop("Name"),
 					  gettext_noop("Owner"),
 					  gettext_noop("Location"));
@@ -235,15 +235,34 @@ describeTablespaces(const char *pattern, bool verbose)
 		printACLColumn(&buf, "spcacl");
 		appendPQExpBuffer(&buf,
 						  ",\n  spcoptions AS \"%s\""
-						  ",\n  pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(oid)) AS \"%s\""
-						  ",\n  pg_catalog.shobj_description(oid, 'pg_tablespace') AS \"%s\"",
+						  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+						  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_size(tblspc.oid))\n"
+						  "       ELSE 'No Access'"
+						  "  END as \"%s\"",
 						  gettext_noop("Options"),
-						  gettext_noop("Size"),
+						  gettext_noop("Size"));
+		if (pset.sversion >= 200000)
+			appendPQExpBuffer(&buf,
+							  ",\n  CASE WHEN dbsub.dattablespace OPERATOR(pg_catalog.=) tblspc.oid OR\n"
+							  "               pg_catalog.has_tablespace_privilege(tblspc.oid, 'CREATE') OR\n"
+							  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
+							  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_tablespace_avail(tblspc.oid))\n"
+							  "       ELSE 'No Access'"
+							  "  END as \"%s\"",
+							  gettext_noop("Free"));
+		appendPQExpBuffer(&buf,
+						  ",\n  pg_catalog.shobj_description(tblspc.oid, 'pg_tablespace') AS \"%s\"",
 						  gettext_noop("Description"));
 	}
 
 	appendPQExpBufferStr(&buf,
-						 "\nFROM pg_catalog.pg_tablespace\n");
+						 "\nFROM pg_catalog.pg_tablespace tblspc\n");
+	if (verbose)
+		appendPQExpBufferStr(&buf,
+							 "CROSS JOIN (SELECT dattablespace FROM pg_catalog.pg_database db\n"
+							 "  WHERE db.datname OPERATOR(pg_catalog.=) pg_catalog.current_database()) dbsub\n");
 
 	if (!validateSQLNamePattern(&buf, pattern, false, false,
 								NULL, "spcname", NULL,
@@ -986,7 +1005,8 @@ listAllDbs(const char *pattern, bool verbose)
 	printACLColumn(&buf, "d.datacl");
 	if (verbose)
 		appendPQExpBuffer(&buf,
-						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT')\n"
+						  ",\n  CASE WHEN pg_catalog.has_database_privilege(d.datname, 'CONNECT') OR\n"
+						  "               pg_catalog.pg_has_role('pg_read_all_stats', 'USAGE')\n"
 						  "       THEN pg_catalog.pg_size_pretty(pg_catalog.pg_database_size(d.datname))\n"
 						  "       ELSE 'No Access'\n"
 						  "  END as \"%s\""
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index f8a021987b5..9c04c88225f 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7859,6 +7859,14 @@
   descr => 'total disk space usage for the specified tablespace',
   proname => 'pg_tablespace_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'name', prosrc => 'pg_tablespace_size_name' },
+{ oid => '6015',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'oid', prosrc => 'pg_tablespace_avail_oid' },
+{ oid => '6016',
+  descr => 'free disk space for the specified tablespace',
+  proname => 'pg_tablespace_avail', provolatile => 'v', prorettype => 'int8',
+  proargtypes => 'name', prosrc => 'pg_tablespace_avail_name' },
 { oid => '2324', descr => 'total disk space usage for the specified database',
   proname => 'pg_database_size', provolatile => 'v', prorettype => 'int8',
   proargtypes => 'oid', prosrc => 'pg_database_size_oid' },
diff --git a/src/test/regress/expected/tablespace.out b/src/test/regress/expected/tablespace.out
index f0dd25cdf0c..12a78c77e05 100644
--- a/src/test/regress/expected/tablespace.out
+++ b/src/test/regress/expected/tablespace.out
@@ -20,6 +20,27 @@ SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
  {random_page_cost=3.0}
 (1 row)
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+ ?column? | ?column? | pg_tablespace_size 
+----------+----------+--------------------
+ t        | t        |                  0
+(1 row)
+
+SELECT pg_tablespace_size('missing');
+ERROR:  tablespace "missing" does not exist
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+ ?column? | ?column? | ?column? 
+----------+----------+----------
+ t        | t        | t
+(1 row)
+
+SELECT pg_tablespace_avail('missing');
+ERROR:  tablespace "missing" does not exist
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 -- This returns a relative path as of an effect of allow_in_place_tablespaces,
diff --git a/src/test/regress/sql/tablespace.sql b/src/test/regress/sql/tablespace.sql
index c43a59e5957..91152335459 100644
--- a/src/test/regress/sql/tablespace.sql
+++ b/src/test/regress/sql/tablespace.sql
@@ -17,6 +17,16 @@ CREATE TABLESPACE regress_tblspacewith LOCATION '' WITH (random_page_cost = 3.0)
 -- check to see the parameter was used
 SELECT spcoptions FROM pg_tablespace WHERE spcname = 'regress_tblspacewith';
 
+-- check size functions
+SELECT pg_tablespace_size('pg_default') BETWEEN 1_000_000 and 10_000_000_000, -- rough sanity check
+       pg_tablespace_size('pg_global') BETWEEN 100_000 and 10_000_000,
+       pg_tablespace_size('regress_tblspacewith'); -- empty
+SELECT pg_tablespace_size('missing');
+SELECT pg_tablespace_avail('pg_default') > 1_000_000,
+       pg_tablespace_avail('pg_global') > 1_000_000,
+       pg_tablespace_avail('regress_tblspacewith') > 1_000_000;
+SELECT pg_tablespace_avail('missing');
+
 -- drop the tablespace so we can re-use the location
 DROP TABLESPACE regress_tblspacewith;
 
-- 
2.53.0


--mAXE2ujK8RZQKpWZ--






^ permalink  raw  reply  [nested|flat] 1192+ messages in thread


end of thread, other threads:[~2026-07-21 13:08 UTC | newest]

Thread overview: 1192+ messages (download: mbox mbox.gz follow: Atom feed)
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2019-09-12 14:35 [PATCH] ERROR out early on attempt to touch user indexes while they are being (re)built. Arseny Sher <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2019-11-08 13:12 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2024-03-29 15:43 [PATCH v8] Avoid orphaned objects dependencies Bertrand Drouvot <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v5] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2025-03-14 15:29 [PATCH v4] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v7] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>
2026-07-21 13:08 [PATCH v6] Add pg_tablespace_avail() functions Christoph Berg <[email protected]>

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